Any reasons to put Cloud Manager in Cloud? what is the minimum disk space for OnTap Cloud to run?

[heightsnj]

Cloud Manager can run in the cloud or in your network. 

I am just wondering if there are reasons that we have to put it in Cloud?

2nd, How much space will OnTap Cloud take, or what is minimum space required to run OnTap cloud?

[AlexDawson]

There's a number of scenarios that spring to mind - If your data all lives in the cloud, and you have no on-premises environment suitable, you can run it in the cloud to manage your cross cloud instances. You might also have a DR process where you need to initiate activities with it so you can't have a dependency for on-premises software.